Adam Clarke on Heb 4:1 and 'seem': Lest any of us should actually come short of it; i.e. miss it. See the note on the verb δοκειν, to seem, Luke 8:18;
Luke 8:18 KJV "Take heed therefore how ye hear: for whosoever hath, to him shall be given; and whosoever hath not, from him shall be taken even...