13:4 laid aside his garments. On an earthly scale, this was analogous to when He emptied Himself of His heavenly vestures to come to earth, where He “took upon Him the form of a servant” (Philippians 2:7). When He again took up His garments (John 13:12), it would be analogous to Philippians 2:9-10, when He returned to heaven.
13:5 wash the disciples’ feet. Instead of serving each other, the disciples shortly before had been arguing who would be the greatest among them (Luke 22:24-27). This action of their Master convicted them, and they never argued this point again.