Can he delay washing his feet until he has finished doing ghusl?

The ghusl that is prescribed in sharee’ah is all the same, whether it is for Jumu’ah, Eid or janaabah. It is mustahabb to start with wudoo’, then to pour water over all of the body, starting on the right side. See question no. 10790. 

Secondly: 

If a person does wudoo’ at the beginning of his ghusl, he may wash his feet with wudoo’ or delay it until he has finished his ghusl. Both are proven from the Messenger (peace and blessings of Allah be upon him). 

According to a hadeeth narrated by ‘Aa’ishah (may Allah be pleased with her) she said: When the Messenger of Allah (peace and blessings of Allah be upon him) did ghusl in the case of janaabah, he would start by washing his hands, then he would pour water with his right hand into his left and wash his private part. Then he would do wudoo’ as for prayer, then he would take water and make it reach the roots of his hair, using his fingers. When he saw that it was thoroughly wetted, he would pour three handfuls of water over his head. Then he would pour water over the rest of his body. Narrated by al-Bukhaari (273) and Muslim (316). 

This indicates that he (peace and blessings of Allah be upon him) washed his feet when he first did wudoo’. 

According to a hadeeth narrated by Maymoonah (may Allah be pleased with her), she said: I brought the Messenger of Allah (S) water to do ghusl from janaabah. He washed his hands two or three times, then he put his hand in the vessel and poured some water over his private part and washed it with his left hand. Then he struck his left hand on the floor and rubbed it vigorously. Then he did wudoo’ as for prayer, then he poured three handfuls of water over his head, then he washed the rest of his body. Then he moved away from the spot where he had been standing and washed his feet. Narrated by al-Bukhaari (265) and Muslim (317). 

Based on this, both ways are permissible, either washing the feet when doing wudoo’ or leaving them until the end of ghusl. 

Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) favoured the view that it is better to wash the feet when doing wudoo’, unless one has an excuse. He said in al-Sharh al-Mumti’ (1/213): 

The phrase “he washed his feet in another place” means: when he had finished ghusl he washed his feet in a place other than the first place. 

Is seems from the author’s words that it is a confirmed Sunnah, even if the place is clean as in our bathrooms nowadays. 

It seems to me that he should wash his feet in another place if he needs to, such as if the floor is made of dirt, because if he washes them his feet will get dirty from the floor. 

This is indicated by the fact that according to the hadeeth of ‘Aa’ishah, the Prophet (peace and blessings of Allah be upon him) did not wash his feet after ghusl, and the report that he washed his feet is weak. The correct view is that he washed his feet in the hadeeth of Maymoonah only. End quote. 

Thirdly: 

The ghusl after which wudoo’ is not required is ghusl in the case of major impurity (janaabah, menses and nifaas). With regard to all other kinds of bathing, wudoo’ is still required.  

See also questions no. 5032 and 68854. 

And Allah knows best.