What does the cryptic crossword clue "What's that you said about Foot's bulk? (4)" mean?

The wordplay uses a reversal. EH (reversal="what did you say?") + FT (synonym="FT") = HEFT The answer is HEFT.

What's that you said about Foot's bulk? (4)

Guardian Cryptic #29166 | 6 Across | 2023-09-04 flower