Saudi Arabias Deputy Crown Prince and Defence Minister Mohammad bin Salman al Saud has agreed an additional $8bn package of aid, investment and petroleum for Egypt, while on a state visit.
This comes at a crucial time for Egypt, as the countrys foreign reserves were close to slipping into dangerous territory. The widely-accepted minimum is three months of imports, or slightly over $15bn for Egypt.
Since the last round of GCC aid in March, official reserves have fallen to $16.4bn.
This injection of foreign currency will give a cushion while Egypt works to attract investment, boost exports, cut imports and rehabilitate its image with foreign tourists.
Bin Salman reiterated Saudi Arabias deep investment in and support for Egypts development, security and stability.
During the same visit President Abdul Fattah al-Sisi and his Foreign Ministry endorsed bin Salmans newly announced Islamic military coalition. It resembles al-Sisis plans for a pan-Arab military coalition to fight terrorist groups in the region, but with Riyadh in charge.
From press reports in Pakistan, it appears that not all 34 members of the coalition are fully supportive of bin Salmans plans.
Egypts support will be crucial. Although Saudi Arabias army has vastly superior weapons and technology, it is reluctant to commit ground troops. Egypt has much higher troop numbers, reflecting its larger population.
Cairo refused to send its army to fight with the Saudi Arabian-led coalition in Yemen, recalling its own disastrous war there in the 1960s.
Egypt has accepted $1.3bn a year of US military aid, in return for upholding a peace treaty with Israel, since 1979. A similar arrangement could be in the making with Riyadh.