Charles Ellicott Commentary 2 Samuel 13:37

"But Absalom fled, and went to Talmai the son of Ammihur, king of Geshur. And [David] mourned for his son every day." — 2 Samuel 13:37 (ASV)

Went to Talmai. This refers to his maternal grandfather (see Note on 2 Samuel 3:2–5). This verse may be considered parenthetical. For example: The king’s sons came... and wept sore. (Only Absalom fled and went to... Geshur.) In this case, the omission of “David” in the latter clause of the verse is explained, as the subject is easily supplied from 2 Samuel 13:36.

For his son every day. Amnon is certainly the son meant here, for whom David continually mourned until his grief was gradually assuaged by the lapse of time.