What does Shastras/ Vedas prescribe in the matter of son/daughter being present near father/mother at the time of their death? I read somewhere it is required that a son be present with parent at the time of their death, which is considered as a factor in them attaining moksha. Does it vary for father / mother? Is it required according to Shastras that son be present or daughters presence is also considered on par?
There is one sanskrit shloka from "Garuda Purana" pointing towards your question about Son/daughter or children being present near parents during time of departure. This shloka from Garuda Purana (PDF Download Page) says -
प्रयाणकाले संस्मरेत्ताक्षयस्वाहम नारायणं निगृणं विश्वमूर्तिम।
पुत्रादिनाम चुंबने चैव काले सुवेंणहस्तु संस्मरेत्कृष्णमेव ।।
Prayanakale SamsmrettakshayaSwaham Narayanam Nigrunam Vishmurtim Putraadinam Chumbane Kaale Suvenhastu SansmretKrishnmeva
Meaning - When he (Someone) is on verge of death he should remember the attributeless and the omnipresent Narayana and his vehicle Garuda. When he kisses his son and other boys he should remember Krishna holding venu(flute) in his hands.
Description: From above shloka it shows that , it's important thing that the children should be present near to a person , as it says " when kissing children , one should remember lord Krishna" Who grants Moksha"
If while dying a person is some how able to recite God's names that is sure to give him mukti(or moksha or salvation).
You can see this question for example.
But it is very rare that a person will be able do so.Mostly he/she would be in a state of unconsciousness or otherwise that won't enable him (or her) to chant anything for that matter.
Maharshi Parashara mentions this among "Mumurshu Prayaschitta":
Paraashara Muni explains the Mumursha prayaschitta vidhi as follows:.........Shiva Shiva Shiva cheti vyaaharanvai trivaaram tyajati nija tanuh, yasvaayushonantyakshane- smin bhavati bhava bhayaanaa, Chhedakah purva shabdo na bhavata itaroudvou kalpitaatyopakarou/
Some how if the dying person is enabled to sing in praise of Govinda or atleast hear the hymn would most positively purify his heart and soul. Pronounciaton of Shiva-Shiva- Shiva shabdas thrice over should destroy the fears of death and serve as the pointer to Moksha!
Maharshi Vishnu(the author of Vishnu Smriti,one of the main Dharma Shastras) desires that :
the sons and relatives ought to whisper into the person’s right ear of Punya Suktas and Mantraksharaas as they realise of risk of life.
So,in case the dying person is himself not able to chant the Govinda or the Shiva names during death, someone else can whisper the same names in his ears.It will have the same effect.And who better to do that than the person's own sons or daughters or the near and dear ones?
Maharshi Vashista(the author of Vashishta Dharma Sutras) advises on the same lines as follows:
Pitrurmarana kaaletu runamochanaat, Mastakastu samaadaaya dakshinasyatu jaanuni/ Shraavayetpunya sultaani punya mantraaksharaani, tatastu nirgate vaayou kushaagreshu vinikshipet/
To secure ‘Pitru runamochana’ the sons should keep the father’s head on their right thighs and enable him to hear punyasuktas and after the praana vayu and breathing stops ticking then rest the body on darbhas!
So,that is why i think the presence of sons /daughters is desired during the time of their parents' death.
As you can see,in this way the parents can secure moksha & a son can get rid of his Pitru Rina.