Should the four rak'ahs before Dhuhr be long or short?

A person sent a question to Hazrat Aisha (may Allah be pleased with her) asking which prayer the Prophet Muhammad (peace and blessings be upon him) liked to observe most regularly. She replied that the Prophet (peace and blessings be upon him) used to perform the four rak'ahs before Zuhr regularly, and he would prolong the standing in them and perform the bowing and prostration in an excellent manner.

Hazrat Ibn Umar (may Allah be pleased with them both) used to lengthen the four rak'ahs before Zuhr.

It is narrated similarly through another chain.

Hazrat Hasan bin Ali (may Allah be pleased with him) used to perform four rak'ahs before Zuhr at length. Hazrat Ibn Aun says that if he recited quickly, he would recite from the long (surahs), and if he recited slowly, he would recite from the medium (surahs).

6088 - Abu Awn said: If he is quick in recitation, then from the long (surahs), and if he is slow in recitation, then from the mi'in.

Hazrat Hudhaifah (may Allah be pleased with him) bin Asid says that I saw Hazrat Ali (may Allah be pleased with him) perform four long rak'ahs after the sun had declined.

Abdur Rahman bin Badeel narrates that the person most familiar with the conditions of Hazrat Abdullah informed me that after the decline of the sun, he would perform four long rak‘ahs in his house, then when the muezzin would give the call to prayer, he would come outside and remain seated in the mosque until the prayer was established.

Hazrat Umar recited Surah Qaf in the four rak'ahs before Zuhr.