The view of those who sufficed with the iqamah while travelling

It is narrated from Nafi' that Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) would not do more than the iqamah for the prayer while travelling (that is, he would not give the adhan), except for the morning prayer, for which he would give the adhan and the iqamah, and he would say: The adhan is for the imam with whom the people gather.

(a) Abu al-Zubayr said: I asked Sayyiduna Abdullah bin Umar (may Allah be pleased with them both): Should I give the adhan while travelling? He said: For whom would you give the adhan? For the mice?
(b) The Shaykh said: The position of Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) would be plausible, were it not for the hadith of Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) about the adhan in the wilderness, and the hadith of Sayyiduna Anas bin Malik (may Allah be pleased with him) and others about the shepherd's adhan. In all of these hadiths there is evidence that giving the adhan is a sunnah, even if a person is alone. The hadith of Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) is taken as evidence that leaving the adhan while travelling is a lesser matter than leaving it when resident.
(c) It is narrated from Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) that he said concerning the traveller: If he wishes, he gives the adhan and the iqamah, and if he wishes, he gives the iqamah. Some people have narrated the hadith of Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) as marfu' (from the Prophet), and that is a gross error.