Arab governments led by Egypt, Saudi Arabia and Jordan have given their backing to a new government without the Islamist movement Hamas. Abbas formed the cabinet last month after Hamas took control of the Gaza Strip in fighting with Fatah.
The United States and Israel opposed the Hamas-led government because Hamas refused to renounce armed struggle against Israel or recognise the Israeli state.
"Maintain the way of jihad and preaching which has spread among the Muslim Palestinian people. Support it and beware of it easing up, and ward off the danger of those who are laying in wait," said a June 30 statement published on Islamist Web sites.
The document was signed by 16 scholars who are leading figures in Saudi Arabia’s powerful religious establishment, including Abdul Rahman Al Barrak and Nasser Al Omar.
Saudi Arabia, home to Islam’s holiest sites and a leading Muslim power, was the driving force behind an Arab initiative offering Israel peace if it returns all the territories it seized during the 1967 Middle East war.
Israel and the United States want Saudi Arabia to join public talks between Israel and Arab officials on pursuing the peace plan, but Saudi leaders have so far resisted the calls.
Saudi authorities have tried to clamp down on charity funding which reaches Hamas.
But the scholars said: "It is our right to help them (Muslims) financially and morally and giving alms is a great moral virtue … we warn against letting down our brothers in Palestine and in Gaza in particular."