De profundis

They further engage, that the charity-boys of the priory, shall, every night forever, sing at the said chapel in the honour of the blessed Virgin Mary, the anthem Salve Regina, or Ave Regina, and after it say the psalm De profundis, with the prayer Fidelium, or Inclina, for the souls of the father and mother of the bishop, and for his soul after his decease, and for the souls of all the faithful deceased...