Solomon
Proverbs 30:2ESV·traditional attribution

Surely I am too stupid to be a man. I have not the understanding of a man.

Matthew Henry Presbyterian @wholebiblehenry

Some make Agur to be not the name of this author, but his character; he was a collector (so it signifies), a gatherer, one that did not compose things himself, but collected the wise sayings and observations of others, made abstracts of the writings of others, which some think is the reason why he says (Pro 30:3), "I have not learned wisdom myself, but have...

Commenting on Proverbs 30:1-6

John Gill Reformed Baptist @doctorgill

Surely I am more brutish than any man,.... "Every man is become brutish in his knowledge"; man in his original state was a knowing creature but sinning lost his knowledge, and "became like the beasts that perish"; hence we read of the "brutish among the people": but Agur thought himself not only brutish among the rest, but more brutish than any.

Jamieson-Fausset-Brown Reformed @jfbcommentary

brutish--stupid, a strong term to denote his lowly self-estimation; or he may speak of such as his natural condition, as contrasted with God's all-seeing comprehensive knowledge and almighty power. The questions of this clause emphatically deny the attributes mentioned to be those of any creature, thus impressively strengthening the implied reference of the former to God (compare Deu 30:12-14; Isa 40:12; Eph 4:8).