The talks on Sunday between Mossad head David Barnea, Qatar's prime minister and Egyptian officials will focus on remaining gaps between Israel and Hamas including over prisoner releases and humanitarian aid, the source said.
Israel had said on Friday it would be sending a delegation to Doha but did not spell out when it would do so or who would take part.
Prime Minister Benjamin Netanyahu was expected to convene the security cabinet before the talks.
Israeli officials were not immediately available to comment on Saturday, the Jewish Sabbath.
Barnea was involved in previous significant pushes for a deal.
A short-lived truce in November was agreed and came into effect after his participation in talks in Doha.
His last meeting with Qatar's prime minister in January led to a proposal for a temporary ceasefire that Hamas ultimately rejected.
Hamas this week presented a new ceasefire proposal to mediators and Israel's ally the United States that includes the release of Israeli hostages in exchange for freedom for Palestinian prisoners.
A ship belonging to the Open Arms aid group has approached the shores of the Gaza Strip. (AP PHOTO)
Repeated efforts to agree a ceasefire and exchange hostages for prisoners have fallen apart this year despite mounting international pressure over the human cost of Israel's ground and air assault in Gaza.
The war began on October 7 when Hamas sent fighters into Israel, killing 1200 people, mostly civilians, and seizing 253 hostages according to Israeli tallies.
Israel's military campaign has killed more than 31,500 Palestinians, about 70 per cent of them women and children, according to the health ministry in Hamas-run Gaza.
Netanyahu's office on Friday said he had authorised a plan to attack the Gaza city of Rafah on the southern edge of the shattered Palestinian enclave where more than half of its 2.3 million residents are sheltering after five months of war.
Global allies and critics have urged Netanyahu to hold off attacking Rafah, fearing mass civilian casualties.
But Israel says it is one of the last strongholds of Hamas whom it has pledged to eliminate and that residents will be evacuated.
US national security spokesman John Kirby said the United States had not seen the Rafah plan but would like to.
He told a regular briefing a Hamas ceasefire-for-hostages proposal was within the bounds of what was possible and expressed cautious optimism about it.
An Israeli statement said the Israeli Defence Force was "preparing operationally and for the evacuation of the population" of Rafah.
It gave no time frame and there was no immediate evidence of extra preparations on the ground.
An aid ship carrying 200 tonnes of food reached the coast of the Gaza Strip on Friday in a bid to ease the hunger crisis facing the enclave.
The Open Arms vessel could be seen in the distance off the beach of the coastal strip, where it had been towed from Cyprus on Friday.
The charity World Central Kitchen aims to deliver the aid on a temporary jetty although precise details of how supplies would reach shore have not been made clear.
