John 13:14

Hence the a fortiori argument: εἰ οὖν ἐγὼ ἔνιψα … πόδας, “if I then, Lord and Teacher, washed your feet, ye also ought (ὀφείλετε denoting moral obligation) to wash one another's feet”. “It is not the act itself, but its moral essence, which after His example He enjoins upon them to exercise.” Meyer. This has sometimes been considered a command enjoining the literal washing of the feet of poor saints: and was practised in England until 1731 by the Lord High Almoner, and is still practised by the Pope on Maundy Thursday (Dies Mandati), the day before Good Friday. See also Church's Anselm, p. 49. The ancient practice is discussed in Augustine's Letters, 55, to Januarius, c. 33. It at once took its place as symbolic of all kindly care of fellow-Christians, see 1 Timothy 5:10.