Responsorium Breve

Psalm 36:31 (Vulgate) continues the preceding verse. 'Lex Dei eius in corde ipsius' (The law of his God is in his heart) fulfills Jeremiah 31:33's new covenant promise - law internalized, not merely external. The consequence 'non supplantabuntur gressus eius' (his steps shall not be supplanted/tripped) uses wrestling imagery (cf. Jacob at Jabbok) - the righteous man cannot be thrown. At None, Christ's hour of death, this responsory promises that the confessor whose heart contained God's law walked surely through life's combat and cannot be overthrown even by death.