Forming rows for prayer

Sayyiduna Jabir (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "Establishing the row is part of the completion of the prayer."
Imam Ahmad, Imam Abu Ya'la and Imam Tabarani recorded it, the latter in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat; its chain contains Abdullah bin Muhammad bin Aqil, about whom there is disagreement as to whether he can be used as evidence.

Sayyiduna Abu Hurayrah (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "Establish the rows well in the prayer."
Imam Ahmad recorded it, and its narrators are the narrators of the Sahih.

Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "I see behind me just as I see in front of me; so straighten your rows, and perform your bowing and prostration well."
Bazzar recorded it, and its narrators are thiqat (trustworthy).

Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) says: I remember about ourselves (that is, the Companions) that (in the blessed time of the Prophet (peace and blessings be upon him)) the prayer would not begin until the rows were complete.
Imam Ahmad recorded it, and its narrators are the narrators of the Sahih.

Sayyiduna Abu Umamah (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "Either you will straighten the rows, or your faces will be effaced; and either you will lower your gazes, or your sight will be snatched away."
Imam Ahmad and Tabarani recorded it in al-Mu'jam al-Kabir; its chain mentions that Abdullah bin Zahr narrated it from Ali bin Yazid, and both of these narrators are da'if (weak).