بسم الله الرحمن الرحيم
There is neither any collective amal (practice) in Shariah after enshrouding and burying the dead as per the sunnah method nor any particular day or method is fixed for isal-e-sawab. Therefore, all the customs observed from 2nd to 40th day are no doubt innovations (bid’aat), Muslims must avoid them. The hadith warns:
من أحدث في أمرنا ھذا ما لیس منہ فھو رد (مشکوۃ شریف، س 27 بحوالہ صحیحین)
However, it is lawful rather good if the family members, relatives and friends of the dead do isal-e-sawab individually without specification of date and method, to visit the house of the deceased once for condoling the aggrieved family members within two three days of death and to visit the graves occasionally and pray for the dead and so on. And it is desirable (mustahab) for neighbours and distant relatives to send cooked meal to the house of the dead for 2-3 times and to feed them if they are not ready for that. It is mentioned in hadith:
اصنعوا لآل جعفر طعاما فقد جاءھم ما یشغلھم (شامی 3:148، ط زکریا دیوبند)
And in some areas, the family of the deceased person arranges feast or party, it is unlawful and bid’ah, it must be avoided.
Allah knows Best!
Darul Uloom Deoband