Commento su Genesi 38:17

ערבון means a PLEDGE.

עד שלחך. The reason why we have the “weak” mode, i.e. the conjugation kal instead of the transitive conjugation hiphil, is to indicate that Yehudah would send a messenger to deliver the kid to Tamar. We find the use of the conjugation kal in connection with the sending of gifts especially, as for instance in 32,19 where Yaakov had instructed his messengers to Esau to describe the gift in such terms. (מנחה היא שלוחה) We find it again in verse 23 of our chapter where Yehudah says הנה שלחתי הגדי הזה, “here, I have sent this kid, etc.”

אם תתן ערבון, if you are prepared to give me such tokens I am willing to sleep with you as you requested.