Poole's Outline of 1 Samuel 21:1, 2: David's Flight to the Tabernacle
Verse 1: Then came David to Nob to Ahimelech the priest (1 Sam. 14:3, called Ahiah; called as Abiathar, Mark 2:26): and Ahimelech was (1 Sam. 16:4) afraid at the meeting of David, and said unto him, Why art thou alone, and no man with thee?
[David came to Nob] It is called Nob, but here the local ה is added (Munster). There were two cities of Nob, one on the other side of Jordan, Numbers 32:42; Judges 8:11; the other on this side of Jordan, in the confines of the tribes of Judah and Benjamin (Lapide). The latter was in the tribe of Benjamin near Anathoth, where a habitation and field was assigned to that [priestly] family, Nehemiah 11:32; 1 Kings 2:26 (Piscator out of Junius). That it was not very far from Jerusalem, is sufficiently indicated in Isaiah 10:32 (thus Sanchez, Menochius, Junius, Piscator, Malvenda). [Most interpreters take this of the Benjamite Nob; but others of the trans-Jordanian Nob (thus Serarius, Mariana).] The tabernacle was there after Eli died; but the ark was in Kirjath-jearim, 2 Chronicles 1 (Mariana). It does not appear to treat of the Nob on this side of Jordan, because it was near to Gibeah of Saul. But David, in verse 5, says that he went forth thence not on the same day, but yesterday and the day before (Serarius). [But the proof does not appear to be sufficiently firm; for David did not come thence directly, neither are all the things that David says here agreeable to the truth.] Moreover, that Nob was a city of priests, which they were inhabiting, is evident from this passage and 1 Samuel 22:19 (Malvenda). But neither Nob is listed among the priestly cities, Joshua 21. Responses: 1. That afterwards more cites than those forty-eight were possessed, or inhabited, by the priests, or the Levites, is evident from 1 Chronicles 6 (Serarius). 2. This city passed to the priest on occasion, as it appears, of the transporting of the Tabernacle there; which the priests were obliged to serve (Lapide). Here David comes, 1. because he was lacking things necessary for nourishment and life, which he was able to have here (Sanchez). 2. So that he might consult God through the priest (Menochius). 3. So that he might pray more fervently in the sacred place, that God might bless his flight (Martyr).
Nob; a city of priests, as it is called 1 Samuel 22:19; either, 1. Because it was assigned to the priests. For though it be not expressed by this name among their cities, Joshua 21, yet it might be one of those cities there named by some other name, which name might be changed; or another new name added to the old for some reason now unknown, as was very usual among the Hebrews: compare 1 Chronicles 6. Or, 2. Because it was now inhabited by the priests for the service of the tabernacle, which now was here; as appears from 1 Samuel 21:7, 9; for as the kings of Israel were to consult with God’s oracle in all their weighty affairs, so they endeavoured to have it in or near their own habitations. Hence it was first carried by Joshua to Shiloh in his tribe of Ephraim; and afterwards by David into his tribe and city; and now, as it seems, had been by Saul carried to Nob, a city in the tribe of Benjamin, Nehemiah 11:32, near to Anathoth, 1 Kings 2:26. Hither David resorted, partly for a supply of his necessities, which he supposed he might receive here, without danger of being betrayed into Saul’s hands; and principally, that in this great distress, and his resolution of going out of the kingdom, he might seek and receive comfort and counsel from the Lord.
[To Ahimelech] In Mark 2:26 he is Abiathar. Therefore, either both father and son had two names (certain interpreters in Malvenda); or Abiathar is named there, 1. Because he was present with his father then (Malvenda). 2. Because, with his father absent or ill, he was attended to his duties (Lapide). 3. Because he was more well known than his father, for the priesthood, with his father slain, was immediately obtained and long maintained. Thus Salian, Mariana, Sà (Tirinus). [Concerning this question, see more things on Mark 2.]
Ahimelech the priest, to wit, the chief priest, brother to that Ahiah, 1 Samuel 14:3; and he being now dead, his successor in the priesthood, for they were both sons of Ahitub, 1 Samuel 14:3; 22:11. Ahimelech was afraid; suspecting some extraordinary cause of his coming in such a manner, and fearing the worst, as men usually do in such cases.
[Why art thou alone, etc.?] But the difficulty here is weighty: For others were with him, as Christ testifies, Matthew 12; Mark 2 (Sanchez). And below Ahimelech asks, if they are clean, etc. (Lyra). Response 1: He is alone in comparison with those that were wont to go with him. Thus we say, none are in the forum, when few are present (Lyra). He was alone, that is, with only two or three (Menochius). The same is held by Dionysius, Hugo, Athanasius, Abulensis. Thus they call one fasting, who relaxes his fast with a little food; and naked, who is poorly clothed. This does not satisfy; for David both hid alone, and come into the land of the Philistines alone. Neither would servants have come without provisions (Sanchez). Response 2: David come to Ahimelech without any attendant, but he had companions in another place, with whom he then shared the loaves (Menochius out of Salian, similarly Martyr, Sanchez). That is, certain faithful servants of David were summoned by Jonathan, and informed by him as to where he had fled: Consequently, they, in zeal to overtake and accompany their lord, had prepared no food for themselves. Therefore, David came to them loaded with bread (Sanchez out of Tostatus). You will say: But David went alone into the land of the Philistines. Response: It did not appear to David safe enough to have a band in hostile territory. Wherefore he ordered them to return from whence they had come forth (Sanchez).
Why art thou alone? for though David had some servants and companions, as is manifest from 1 Samuel 21:4, 5, and from Matthew 12:3, 4, whom Jonathan probably had sent to a place appointed to serve and guard him; yet they were left at another place, as David himself affirmeth, 1 Samuel 21:2. And David was now alone, as also he was when he fled to Achish, verse 10.
Verse 2: And David said unto Ahimelech the priest, The king hath commanded me a business, and hath said unto me, Let no man know any thing of the business whereabout I send thee, and what I have commanded thee: and I have appointed my servants to such and such a place.
[The king hath commanded, etc.] This lie was officious (Lyra, Estius, Malvenda, Junius, Piscator), out of human infirmity, so that he might conceal his flight (Piscator); which he, with Euripides and Diphilus, esteemed permissible in order to avoid disaster. It is to be pardoned to a certain degree in those times, when eternal life was so much concealed (Grotius).
The king hath commanded me a business: this seems to be a plain lie, extorted from him by fear and necessity. But as it was officious for himself, so it was pernicious to all the priests there. Whence David afterwards declares his repentance for this sin of lying, Psalm 119:29.
[I have appointed to the young men such and such a place,וְאֶת־הַנְּעָרִ֣ים יוֹדַ֔עְתִּי אֶל־מְק֥וֹם פְּלֹנִ֖י אַלְמוֹנִֽי׃] Verbatim: now, I have caused the young men to know (now, I have indicated to the young men [Munster, Tigurinus], or I have appointed [Pagnine]) such and such a place (Vatablus, Munster, Pagnine, Tigurinus), that is, a certain and fixed place, that is, in which I might find them. The Hebrews make use of these terms, when they want to refrain from proper names. They signify the same thing as δεῖνα, that is, a certain, some, or such, to the Greeks; that is to say, to such and such a place, which in the present circumstances I will not name. See Ruth 4:1 (Vatablus). To I know not which place; or, to which place it does not concern thee to know (Sanchez). Or to the place of a certain one (Junius and Tremellius); to the place, that is, house, or city, of such and such, understanding, man, or of some certain man (Vatablus). To that and that place (Munster); this and that place (Strigelius); to the place of one obscure and unknown (Montanus); a place secret and hidden (or protected [Jonathan]) (Syriac, similarly the Arabic). פְּלֹנִי is the same thing as מְכוּסֶּה/covered, and אַלְמוֹנִי is the same thing as נִסְתָּר/concealed (Munster). The verb יוֹדַעְתִּי is anomalous, in the place of הוֹדַעְתִּי, I caused to know (Buxtorf’s Lexicon, thus Munster). It is also possible that יוֹדַעְתִּי is of a mixed conjugation (Munster). אֶל/to is likewise put in the place of אֶת (Buxtorf).
To such and such a place; to a certain place which is not material nor convenient now to mention, because the whole business requires concealment.
 Hebrew: וַיָּבֹ֤א דָוִד֙ נֹ֔בֶה אֶל־אֲחִימֶ֖לֶךְ הַכֹּהֵ֑ן וַיֶּחֱרַ֙ד אֲחִימֶ֜לֶךְ לִקְרַ֣את דָּוִ֗ד וַיֹּ֤אמֶר לוֹ֙ מַדּ֤וּעַ אַתָּה֙ לְבַדֶּ֔ךָ וְאִ֖ישׁ אֵ֥ין אִתָּֽךְ׃  Hebrew: וַיָּבֹ֤א דָוִד֙ נֹ֔בֶה.  Numbers 32:42: “And Nobah (וְנֹבַח) went and took Kenath, and the villages thereof, and called it Nobah (נֹבַח), after his own name.”  Judges 8:11: “And Gideon went up by the way of them that dwelt in tents on the east of Nobah (לְנֹבַח) and Jogbehah, and smote the host: for the host was secure.”  Hebrew: וַיֹּ֙אמֶר דָּוִ֜ד לַאֲחִימֶ֣לֶךְ הַכֹּהֵ֗ן הַמֶּלֶךְ֮ צִוַּ֣נִי דָבָר֒ וַיֹּ֣אמֶר אֵלַ֗י אִ֣ישׁ אַל־יֵ֧דַע מְא֛וּמָה אֶת־הַדָּבָ֛ר אֲשֶׁר־אָנֹכִ֥י שֹׁלֵֽחֲךָ֖ וַאֲשֶׁ֣ר צִוִּיתִ֑ךָ וְאֶת־הַנְּעָרִ֣ים יוֹדַ֔עְתִּי אֶל־מְק֥וֹם פְּלֹנִ֖י אַלְמוֹנִֽי׃  Diphilus of Sinope (342-291) was a Greek comic poet. Of his one hundred plays, only fragments survive.  Ruth 4:1: “Then went Boaz up to the gate, and sat him down there: and, behold, the kinsman of whom Boaz spake came by; unto whom he said, Ho, such a oneפְּלֹנִ֣י) אַלְמֹנִ֑י)! turn aside, sit down here. And he turned aside, and sat down.”  The Hiphil conjugation frequently conveys a causative sense.  Johann Buxtorf, Sr. (1564-1629) was a renowned Reformed Hebraist, known as the “Master of the Rabbis”. He served as Professor of Hebrew at Basel from 1590 to 1629. Lexicon Chaldaicum, Talmudicum, et Rabbinicum.  The direct object marker.