The war booty belongs to those who were present at the battle

Imam al-Shafi'i (may Allah have mercy on him) says: I learned from most of the people of knowledge whom I have met that Abu Bakr (may Allah be pleased with him) said: "The spoils belong to those who were present at the battle."

Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) dispatched Sayyiduna Ikrimah bin Abi Jahl (may Allah be pleased with him) with five hundred Muslims as reinforcements for Ziyad bin Labid and al-Muhajir bin Abi Umayyah (may Allah be pleased with them both). They reached the army when it had already conquered al-Nujayr in Yemen, and Ziyad bin Labid (may Allah be pleased with him), who was one of those who had been present at Badr, gave them a share in the spoils. Imam al-Shafi'i (may Allah have mercy on him) says: Ziyad wrote about this matter to Abu Bakr (may Allah be pleased with him), and Sayyiduna Abu Bakr (may Allah be pleased with him) replied: "The spoils belong only to those who were present at the battle." He did not consider Ikrimah (may Allah be pleased with him) entitled to any share of the spoils, because he had not been present at the battle. So Ziyad spoke to his companions about it, and they willingly agreed to give a share to Ikrimah and his companions as a voluntary gift from themselves. This is our view.

Tariq bin Shihab says: The people of Basrah fought the people of Nahawand, and they were reinforced by the people of Kufah, whose commander was Ammar bin Yasir (may Allah be pleased with him). They (the people of Kufah) reached them after they had already prevailed over the enemy. The people of Kufah demanded a share of the spoils, while the people of Basrah did not want to give the people of Kufah any share of the spoils. A man from Banu Tamim said to Ammar bin Yasir (may Allah be pleased with him): O you with the cut-off ear, do you want to share with us in our spoils? Ammar's (may Allah be pleased with him) ear had been cut off while he was with the Messenger of Allah (peace and blessings be upon him). So they wrote to Umar (may Allah be pleased with him), and Umar (may Allah be pleased with him) replied: "The spoils belong to those who were present at the battle."

Tariq bin Shihab al-Ahmasi (may Allah be pleased with him) says that Umar bin al-Khattab (may Allah be pleased with him) wrote: "The spoils belong to those who were present at the battle."
This is the authentic report from Umar (may Allah be pleased with him).

Sayyiduna Umar (may Allah be pleased with him) wrote to Sa'd bin Abi Waqqas (may Allah be pleased with him): I am sending you some people as reinforcements. Whoever of them reaches you before the bodies of the slain burst open, give him a share in the spoils.
Imam al-Shafi'i (may Allah have mercy on him) says: This is not established from Sayyiduna Umar (may Allah be pleased with him). If it were established, we would quickly accept it. Then he mentioned how Abu Yusuf contradicted this hadith of Sayyiduna Umar (may Allah be pleased with him).
The Shaykh says: It is munqati' (broken), and its narrator Mujalid is da'if (weak). The chain of the hadith of Tariq bin Shihab (may Allah be pleased with him) is sahih (authentic); there is no doubt about it.
Imam al-Shafi'i (may Allah have mercy on him) says: Something established has been narrated from the Messenger of Allah (peace and blessings be upon him) on this, in agreement with what is narrated from Sayyiduna Abu Bakr and Sayyiduna Umar (may Allah be pleased with them both), but I did not remember it well.
The Shaykh says: Perhaps he meant the hadith of Sayyiduna Abu Hurayrah (may Allah be pleased with him) containing the incident of Sayyiduna Aban bin Sa'id bin al-As (may Allah be pleased with him): when he came to the Prophet (peace and blessings be upon him), he had already conquered Khaybar, and he did not give them a share. This has passed earlier in "Kitab al-Qasm", along with what is narrated on it.

Sayyiduna Ali (may Allah be pleased with him) says: The spoils belong to those who were present at the battle.