פירוש על ברכות 18:21

Therefore R. Johanan's teaching cannot apply to the evening Tefilluh, because "O Lord, open Thou my lips" would constitute an interruption. The importance which this Rabbi attached to uniting the two prayers in the evening is accounted for by Elbogen (J. Q. R. xix. pp. 711 ff.) on the theory that it was intended to abolish the custom of introducing prayers of a personal nature after the Shema' which was likely to destroy the congregational character of the Service. Cf. fol. 31a, p. 206.