Poole's Outline of 1 Samuel 22:20-23: David's Acknowledgement of Responsibility
Verse 20: (1 Sam. 23:6) And one of the sons of Ahimelech the son of Ahitub, named Abiathar, (1 Sam. 2:33) escaped, and fled after David.
[One escaping] Either by flight, or because he had remained at home, so that he might see to the Sacred Rites (Menochius). Therefore, it is probable that Saul now restored the High Priestly Office to the family of Eleazar, and constituted Ahitub, the father of Zadok, as High Priest. Who, with the death of Saul, was indeed received by David into favor, but was not permitted in the High Priestly Office, except as the vicar of Abiathar (Tirinus out of Tostatus).
Abiathar, by his father’s death, was now high priest.
[He fled to David] Whom he followed to Keilah, 1 Samuel 23:7 (Junius, Piscator, Malvenda). From this it is evident that it is a prolepsis (Grotius, Malvenda).
Fled after David, to Keilah, 1 Samuel 23:6, 7.
Verse 21: And Abiathar shewed David that Saul had slain the LORD’S priests.
Verse 22: And David said unto Abiathar, I knew it that day, when Doeg the Edomite was there, that he would surely tell Saul: I have occasioned the death of all the persons of thy father’s house.
[I am guilty of all the souls of thy father, or of the family of thy father (Syriac), אָנֹכִ֣י סַבֹּ֔תִי בְּכָל־נֶ֖פֶשׁ בֵּ֥ית אָבִֽיךָ׃] I have supplied the reason upon every soul of the house of thy father (Pagnine, Montanus, Vatablus, similarly the Dutch), that is, that they might be killed (Vatablus). I was the occasion of the death of all, etc. (Munster, English). I was responsible as to why he was angry against all, etc. (Junius and Tremellius). סָבַב signifies to surround, but here it borrows the signification from the noun, whereby a cause is denoted, namely, סִבָּה (Piscator) (by which noun the Rabbis signify a cause [Munster]). Just as אוֹפָן is a wheel; so in a similar manner a circle is used for a cause, or an occasion. I surrounded, I went around, in every soul, etc.; that is, I devolved the cause and occasion upon every soul, or life, etc. (Malvenda). I have sinned against all the souls, etc. (Arabic). I was the occasion of all killed, etc. (Tigurinus). [נֶפֶשׁ/soul/life appears to be taken as corpse, as is done elsewhere.] I have turned upon every soul, etc., understanding, the sword of Saul; that is, I was responsible for the sword being turned, etc. (certain interpreters in Malvenda). [It is the same verb here as in verses 18, 19, turn thou upon the Priests.] You could render it, I, even I, have beset all, etc., that is, have oppressed, or wound around; that is, have involved in my calamities (Malvenda). I am guilty; from me Saul has taken occasion for slaughter. Note here that David ascribes all the fault, not to Saul, or to Doeg, but to himself alone, who was only the occasion contingently. It is a characteristic of good hearts, says Gregory,to acknowledge fault, where there is none (Menochius).
I knew it; his malice and ambition made me suspect that he would do it.
Verse 23: Abide thou with me, fear not: (1 Kings 2:26) for he that seeketh my life seeketh thy life: but with me thou shalt be in safeguard.
[If anyone seek my soul, he shall seek thy soul also (similarly Kimchi in Munster)] One that shall seek to destroy me, shall seek to destroy thee (Vatablus). That is to say, We have Saul as a common enemy (Vatablus).
[And with me thou shalt be preserved, כִּֽי־מִשְׁמֶ֥רֶת אַתָּ֖ה עִמָּדִֽי׃] Because thou shalt be kept (thou shalt be safeguard [Montanus]) in my hands (Pagnine, Tigurinus, Septuagint, Jonathan), or, with me (Vatablus); that is, I will keep thee, as myself, and as a thing deposited with me (Vatablus). Thou shalt be a custodian with me (Syriac); in custody thou shalt be with me (Munster, Junius and Tremellius). Thou shalt be safeguard. Emphatically stated; that is to say, more than being kept safe, thou shalt be observation and custody itself; thou shalt be kept safe as carefully and securely as possible (Malvenda). I translate it in this way, for thou shalt be with me for safe-keeping; that is, thou shalt be in charge of the safe-keeping of divine worship. מִשְׁמֶרֶת frequently signifies that. This exposition is supported by what is said concerning the ephod, 1 Samuel 23:9; 30:7 (Piscator).
With me thou shalt be in safeguard: Because God will certainly preserve me to the kingdom which he hath promised; and I by his help will protect thee.
 Hebrew: וַיִּמָּלֵ֣ט בֵּן־אֶחָ֗ד לַאֲחִימֶ֙לֶךְ֙ בֶּן־אֲחִט֔וּב וּשְׁמ֖וֹ אֶבְיָתָ֑ר וַיִּבְרַ֖ח אַחֲרֵ֥י דָוִֽד׃  See what things are on 1 Samuel 2:30.  Keilah is about seven miles northwest of Hebron.  Hebrew: וַיַּגֵּ֥ד אֶבְיָתָ֖ר לְדָוִ֑ד כִּ֚י הָרַ֣ג שָׁא֔וּל אֵ֖ת כֹּהֲנֵ֥י יְהוָֽה׃  Hebrew: וַיֹּ֙אמֶר דָּוִ֜ד לְאֶבְיָתָ֗ר יָדַ֜עְתִּי בַּיּ֤וֹם הַהוּא֙ כִּֽי־שָׁם֙ דּוֹיֵ֣ג הָאֲדֹמִ֔י כִּֽי־הַגֵּ֥ד יַגִּ֖יד לְשָׁא֑וּל אָנֹכִ֣י סַבֹּ֔תִי בְּכָל־נֶ֖פֶשׁ בֵּ֥ית אָבִֽיךָ׃  See, for example, Numbers 9:6: “And there were certain men, who were defiled by the dead body of a man (לְנֶ֣פֶשׁ אָדָ֔ם, by the soul of a man), that they could not keep the passover on that day: and they came before Moses and before Aaron on that day…”  1 Samuel 22:17, 18: “And the king said unto the footmen that stood about him, Turn, and slay the priests of the Lord (סֹ֥בּוּ וְהָמִ֣יתוּ׀ כֹּהֲנֵ֣י יְהוָ֗ה); because their hand also is with David, and because they knew when he fled, and did not shew it to me. But the servants of the king would not put forth their hand to fall upon the priests of the Lord. And the king said to Doeg, Turn thou, and fall upon the priests (סֹ֣ב אַתָּ֔ה וּפְגַ֖ע בַּכֹּהֲנִ֑ים). And Doeg the Edomite turned, and he fell upon the priestsוַיִּסֹּ֞ב דּוֹיֵ֣ג הָאֲדֹמִ֗י וַיִּפְגַּע־הוּא֙) בַּכֹּ֣הֲנִ֔ים), and slew on that day fourscore and five persons that did wear a linen ephod.”  Gregory the Great (c. 550-604) was elected Pope in 590. He was a monk, scholar, prolific author, and, having been made Pope, instrumental in reinvigorating the missionary work of the Church.  Hebrew: שְׁבָ֤ה אִתִּי֙ אַל־תִּירָ֔א כִּ֛י אֲשֶׁר־יְבַקֵּ֥שׁ אֶת־נַפְשִׁ֖י יְבַקֵּ֣שׁ אֶת־נַפְשֶׁ֑ךָ כִּֽי־מִשְׁמֶ֥רֶת אַתָּ֖ה עִמָּדִֽי׃  See, for example, Numbers 1:53: “But the Levites shall pitch round about the tabernacle of testimony, that there be no wrath upon the congregation of the children of Israel: and the Levites shall keep the charge of the tabernacle of testimonyוְשָׁמְרוּ֙) הַלְוִיִּ֔ם אֶת־מִשְׁמֶ֖רֶת מִשְׁכַּ֥ן הָעֵדֽוּת׃).” Ezekiel 44:15: “But the priests the Levites, the sons of Zadok, that kept the charge of my sanctuary (שָׁמְר֜וּ אֶת־מִשְׁמֶ֤רֶת מִקְדָּשִׁי֙) when the children of Israel went astray from me, they shall come near to me to minister unto me, and they shall stand before me to offer unto me the fat and the blood, saith the Lord God…”