Mukhtasar Bukhari (Abridged) 382 — Praying voluntary prayers between

Narrated from Sayyiduna Abdullah bin Mughaffal Muzani (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Between every two calls to prayer, there is a prayer." He said this three times (then said): "If anyone wishes to offer it." In another narration, it is stated that the Noble Prophet (peace and blessings of Allah be upon him) said: "Between every two calls to prayer (i.e., the adhan and the iqamah) there is a prayer, between every two calls to prayer (i.e., the adhan and the iqamah) there is a prayer." Then, the third time, he said: "If anyone wishes (he may offer it)."