Is it permissible to perform the four rak'ahs of the Sunnah prayer before Dhuhr with one Tasleem and two Tashahhuds, based on the Hadith: "Four [rak'ahs] before Dhuhr in which there is no Tasleem, the gates of heaven are opened for them"?

The hadith (definition) reported by Abu Ayyub (may Allah be pleased with him) regarding praying four rak'ahs before Dhuhr, "without a salutation in them, the gates of heaven are opened for them," is weak. Its chain of narration revolves around Ubaydah ibn Ma'tab, who is unanimously considered weak. Sheikh Al-Albani graded the hadith as hasan (definition) (good) without the phrase "without a salutation in them."

As for the hadith of Ali (may Allah be pleased with him): "The Prophet (peace and blessings of Allah be upon him) used to pray four rak'ahs before Asr, separating them with the salutation upon the close angels and those Muslims and believers who follow them," Al-Albani graded it as hasan. Scholars have differed regarding the meaning of "separating them with the salutation." Some said it refers to the salutation of concluding the prayer, while others said it refers to sitting for the tashahhud (definition) in the second rak'ah, as it includes the salam.

Sheikh Ibn Baz (may Allah have mercy on him) was asked about praying four rak'ahs before Dhuhr, and he replied: "One should pray two rak'ahs at a time, then give the salam after them. The basis for this is the hadith of Ibn Umar (may Allah be pleased with them both) that the Prophet (peace and blessings of Allah be upon him) said: 'The prayer of the night and day is two by two.' However, if one prays all four together, there is no harm, due to the general wording of some narrations regarding that."