Abu Ishaq states: The people went out for the prayer for rain (istisqa'), and among them was Sayyiduna Zayd bin Arqam (may Allah be pleased with him); there was only one man between him and me. I asked him: "O Abu Amr! How many military expeditions did the Prophet (peace and blessings be upon him) undertake?" He replied: "Nineteen." I asked: "In how many did you yourself take part with him (peace and blessings be upon him)?" He said: "Seventeen." This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim).