Vincent's NT Word Studies
18. How ye hear (pwv). The manner of hearing. Mark has ti, what ye hear; the matter.Seemeth (dokei). Peculiar to Luke. Rev. renders "thinketh he hath," as Jas. i. 26, on which see note. Wyc., guesseth; Tynd., supposeth.
19-21. Compare Matt. xii. 46-50; Mark iii. 31-35.
Come at him (suntucein). Only here in New Testament. The word properly carries the idea of an accidental meeting, and slightly so here. Jesus was lost in the crowd, and his friends could not fall in with him.
22-25; ix. 57-62. Compare Matt. viii. 18-27; Mark iv. 35-41.
Robertson's NT Word Studies
8:18 {How ye hear} (pws akouete). The manner of hearing. #Mr 4:24 has "what ye hear" (ti akouete), the matter that is heard. Both are supremely important. Some things should not be heard at all. Some that are heard should be forgotten. Others should be treasured and practised. {For whosoever hath} (hos an gar ecei). Present active subjunctive of the common verb ecw which may mean "keep on having" or "acquiring." See on Mr 4:25 for discussion. {Thinketh he hath} (dokei ecein), or {seems to acquire or to hold}. Losses in business illustrate this saying as when we see their riches take wings and fly away. So it is with hearing and heeding. Self-deception is a common complaint.