Does "came together" in the Hadith mean that these four things must be done in one day to enter Paradise, or can they be done separately throughout one's life? And what is the meaning of "Paradise becomes obligatory for him," and is it considered a guarantee?

The hadith narrated by Muslim and others with the wording: "They do not combine in a man except that he enters Paradise"; its meaning is: he enters Paradise without reckoning or recompense for bad deeds, for faith alone necessitates entry into Paradise by the grace of Allah Almighty. And his (peace be upon him) saying: "Paradise became obligatory for him" means it was confirmed for him, and he deserved to enter it with the forerunners or without prior punishment. It is a guarantee of entry into Paradise if the conditions of monotheism are met and the impediments of polytheism are absent, as in his (peace be upon him) saying: "Whoever says 'There is no god but Allah,' and disbelieves in what is worshipped besides Allah..." And it is apparent from his (peace be upon him) saying: "Who among you is fasting today?" that this noble promise is linked to the convergence of the mentioned characteristics on a single day and not on separate days, even though each characteristic is a great act of devotion for which its doer is rewarded.