Poole on 1 Samuel 13:8, 9: Saul's Sinful Sacrifice
Verse 8: (1 Sam. 10:8) And he tarried seven days, according to the set time that Samuel had appointed: but Samuel came not to Gilgal; and the people were scattered from him.
[And they were tarrying seven days according to the appointment of Samuel, וַיִּ֣יחֶל׀ שִׁבְעַ֣ת יָמִ֗ים לַמּוֹעֵד֙ אֲשֶׁ֣ר שְׁמוּאֵ֔ל] Verbatim: and he tarried seven days to the time established that Samuel (Montanus), unto the time appointed by Samuel (Syriac, Munster, Tigurinus, similarly Castalio), according to (or after [Jonathan]) the time that Samuel had said (Pagnine, Drusius, Mariana). The Septuagint thus: he delayed seven days for the testimony, just as Samuel had said. They confuse מוֹעֵד, appointed time, with עֵד/testimony. Although by the name of testimony they think here to be signified a stated time, and a certain ordinance. Aquila and Symmachus thus: he waited seven days according to the ordinance of Samuel. Here, אֲשֶׁ֣ר שְׁמוּאֵ֔ל means of Samuel, and so nothing is to be understood. Moreover, in the Kethib it is וַיִּיחֶל, and he waited, and in the Qere, וַיּוֹחֶל, and he waited, which is the future/imperfect Hiphil ofיָחַל (Drusius). Question: Since Saul is here said to have waited for seven days, how is the precept of Samuel said to have been violated by Saul? Response: Because he did not wait for seven whole days (Mendoza out of Gregory and Lyra and Carthusianus, Lapide, thus Estius, Menochius, Tirinus on verse 13). He was held to wait that whole time of day, in which it was lawful to sacrifice (for Samuel was coming to sacrifice); but sacrifices could lawfully be offered until the setting of the Sun, as it is evident out of Exodus 29:38, etc. But he sacrificed earlier; for, with the sacrifice having ended, Samuel came to sacrifice, and so before the setting of the Sun. Moreover, Saul sacrificed either at the dawning of the seventh day, as Tostatus maintains, or, which is more plausible, a few hours before the setting of the Sun, as Carthusianus maintains (Mendoza). Thus Saul, with the waiting of an exceedingly brief time neglected, lost both the temporal kingdom and likewise the eternal kingdom (Mendoza’s Annotations 14:1). And he waited, etc. Samuel had willed that assembly and sacrifice be refrained from, until he himself had arrived. But Saul, since he had awaited him seven days, was unwilling any longer to await the Prophet, the revealer of the Divine will; which was imputed to him as a grievous sin (Grotius).
Seven days; not seven complete days; for that the last day was not finished plainly appears from Samuel’s reproof, which had then been groundless and absurd, and he had falsely charged Saul with breaking God’s command therein, 1 Samuel 13:13. And as Samuel came on the seventh day, and that with intent to sacrifice; so doubtless he came in due time for that work, which was to be done before sun-setting, Exodus 29:38, 39. So Saul waited only six complete days, and part of the seventh, which is here called seven days; for the word day is oft used for a part of the day, as among lawyers, so also in sacred Scripture; as Matthew 12:40, where Christ is said to be in the heart of the earth three days and three nights, that is, one whole day, and part of the other two days. Moreover this place may be thus rendered: He tarried until the seventh day, (as this same phrase is used, Genesis 7:10, Hebrew, until the seventh of the days,) (as the Hebrew ל/lamed is oft taken,) the set time that Samuel had appointed.
[And he came not] That is, until that part of the seventh day, in which Saul despaired of his coming (Mendoza).
[And the people were scattered from him] Not all at once, and suddenly; but continuously through those seven days (Mendoza).
Verse 9: And Saul said, Bring hither a burnt offering to me, and peace offerings. And he offered the burnt offering.
[A burnt offering and peace offerings] From the threefold sort of sacrifices, the burnt offering, the peace offering, and the offering for sin, he offered only the first two; he omitted the third, because he was recalling no sin from which he was desiring to be expiated (Mendoza).
[And he offered the burnt offering] Understand, and the peace offerings, although this is not expressed (Mendoza) [Whether Saul offered by his own hand, or through a priest, is to be discussed in what follows.]
And he offered, etc.: Either himself; or rather by the priest, as Solomon is said to offer, 1 Kings 3:4. Compare 1 Samuel 1:3.
 Hebrew: וַיִּ֣יחֶל׀ שִׁבְעַ֣ת יָמִ֗ים לַמּוֹעֵד֙ אֲשֶׁ֣ר שְׁמוּאֵ֔ל וְלֹא־בָ֥א שְׁמוּאֵ֖ל הַגִּלְגָּ֑ל וַיָּ֥פֶץ הָעָ֖ם מֵעָלָֽיו׃  1 Samuel 13:8a: “And he tarried seven days, according to the set time that Samuel (אֲשֶׁ֣ר שְׁמוּאֵ֔ל)…”  In the Niphal Conjugation.  Genesis 7:10: “And it came to pass after seven days (לְשִׁבְעַ֣ת הַיָּמִ֑ים), that the waters of the flood were upon the earth.”  Hebrew: וַיֹּ֣אמֶר שָׁא֔וּל הַגִּ֣שׁוּ אֵלַ֔י הָעֹלָ֖ה וְהַשְּׁלָמִ֑ים וַיַּ֖עַל הָעֹלָֽה׃