The fatwa, or religious edict, was issued late Saturday by Suleiman al-Daya, a cleric respected by both ultra-conservative Salafis and Hamas. Salafi groups oppose political accommodations with Israel.

“Honoring the truce, which was sponsored by our Egyptian brethren, is the duty of each and every one of us. Violating it shall constitute a sin,” the fatwa read.

The truce, which was struck Wednesday to bring an end to an eight-day Israeli offensive against Gaza militants who fired rockets into Israel, remains fragile, however, and details beyond the initial cease-fire have not yet been worked out. The fighting killed 169 Palestinians, including dozens of civilians, and six Israelis.

The spokesman for Gaza’s Hamas government, Taher Nunu, told reporters Sunday that Hamas is committed to the truce.

“The government reaffirmed its blessing to the agreement sponsored by Cairo and emphasized that it will work to the internal Palestinian consensus and the supreme national interest,” he said, following a government meeting.

Hamas demands that Israel and Egypt lift all restrictions on the movement of goods and people in and out of the Palestinian territory. The restrictions have been imposed since the Islamists seized the territory in 2007.

Israel has eased its full-fledged blockade in recent years, and some goods enter Gaza through smuggling tunnels under the border with Egypt. But Israel has continued to impose strict restrictions on exports and the import of construction materials, which has severely hampered the development of Gaza’s battered economy.

Israel is expected to link a significant easing of the blockade to Hamas’s willingness to stop smuggling weapons into Gaza and producing them there. A top Hamas official said Saturday that the group wouldn’t stop arming itself, suggesting that talks on a new border deal would not go smoothly.

Nunu also told reporters that the offensive inflicted more than $1.2 billion in damage on the Gaza economy, including damage to buildings, infrastructure, agriculture and trade. Israel continues to restrict the inflow of building materials, but Nunu said that talks on lifting those limitations are to begin in meetings scheduled to start in Cairo on Monday.

The government in Gaza has no estimate yet on how long the reconstruction will take. Gaza only recently concluded rebuilding most of the buildings and infrastructure damaged during Israel’s 2009 war in the territory.