for which see FIRM , No. 2, has the meaning "solid" in Hebrews 5:12,14 , of food (AV, "strong"). As "solid" food requires more powerful digestive organs than are possessed by a babe, so a fuller knowledge of Christ (especially here with reference to His Melchizedek priesthood) required that exercise of spiritual intelligence which is derived from the practical appropriation of what had already been received.