who also sat at Jesus’ feet and heard His word.”
There are two elements here: she sat at His feet, and she heard His Word. You must sit at His feet and hear Him for yourself. Entering into the Lord’s thought, becoming acquainted with His Ways as well as His Word, takes the sort of love-devotion Mary demonstrates.
The Greek here is continuous action: she “kept on listening.” Martha listened too, but when she arose to prepare dinner, Mary remained. As we progress we will see that Mary has discovered Spirit and Truth, and from henceforth she is always at the feet of the Lord in one way or the other.