Mukhtasar Bukhari (Abridged) 140 — Considering ablution obligatory

Narrated from Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) sent a man to an Ansari person (to call him), so he came while water (of bathing) was dripping from his head. The Prophet (peace and blessings of Allah be upon him) said: "Perhaps we hurried you (in calling you)?" He replied, "Yes, O Messenger of Allah!" So the Prophet (peace and blessings of Allah be upon him) said: "When there is haste or (for some other reason) there is no ejaculation, then only ablution (wudu) is obligatory upon you (ghusl is not obligatory)." (But this ruling is abrogated.)