im not really sure about any hadiths, but maybe they meant that before you pray, keep your heart clean and not hateful init
like the exact night of layla tul qadr, wasnt revealed to RasoolAllah saw, cause 2 people were quarelling so Allah swt, dint reveal it
so like when you pray your heart should be clear init and shouldnt have any bad feelins, cause it can distract you in salaah
lol i dunno if answered your Q though

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