It is narrated from Sayyiduna Salman (may Allah be pleased with him) that any man who is in a land of shade (wilderness and the like), performs ablution or performs tayammum with clean soil, then gives the adhan for the prayer, then gives the iqamah and prays (in the hadith of Abu al-Abbas: then gives the iqamah for it), leads in prayer such of the soldiers of Allah whose two ends cannot be seen, or he said: whose two sides (al-Taymi was in doubt).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 1906