The prohibition of etnan (harlot’s wage) should take effect retroactively - Since he gave it to her at the outset on condition of intercourse.

Acquire it from now - Before intercourse, it is obvious that it is permitted, for even though he gave it on condition of intercourse, since he gave it to her before intercourse, it is not considered payment for intercourse.

If you will need it, acquire it from now - Therefore the Mishnah needed to teach us that even though he said to her, “It shall not be acquired to you until the moment of intercourse”, since he then said, “If you will need it, acquire it from now,” it is considered a free gift. [Therefore] when she [later] takes it and offers it [as a sacrifice, it is valid].

Since the Master said - In the Tosefta in Kiddushin, chapter 1 (28b).

With THIS lamb - Whenever he gives it to her, it is considered an etnan, because from now she acquires it.

With an unspecified lamb – When he gives it after a period of time, it is not considered an etnan, because only now she acquires it.

A gentile does not acquire with meshichah (pulling/physical delivery), for when Scripture wrote about meshichah, it wrote it regarding Israel (Vayikra 25:14) — “or acquired from the hand of your people.

He had already acquired it - From now, before the intercourse, so how can we call it “he cohabited with her and afterward gave it to her”?

If he did not take it - [Saying "If I don't compensate you] prior to a certain date, then it shall be your etnan”. It is therefore considered as if he cohabited and afterward gave it. However, since from the moment of the intercourse he designated it as a specific security (apoteki), and it was already standing in her courtyard, [the prohibition of] etnan takes effect

Rav Sheshet raised an objection - To R. Yannai.

His workers and his donkey-drivers - [Either] gentiles or amei ha’aretz (unlearned Jews).