They've been doing it on the sly for a few months and most of the weapons have been small arms - rifles, grenade launchers, etc.
Now, they're apparently ready to start giving the Free Syrian Army (FSA) a steady flow of weapons, pay the fighters, while the US helps set up command and control.
Officials in the Saudi capital embraced the idea when it was put to them by Arab officials in May, according to sources in three Arab states, around the same time that weapons started to flow across the southern Turkish border into the hands of Free Syria Army leaders.
Turkey has also allowed the establishment of a command centre in Istanbul which is co-ordinating supply lines in consultation with FSA leaders inside Syria. The centre is believed to be staffed by up to 22 people, most of them Syrian nationals.
The Guardian witnessed the transfer of weapons in early June near the Turkish frontier. Five men dressed in the style of Gulf Arabs arrived in a police station in the border village of Altima in Syria and finalised a transfer from the Turkish town of Reyhanli of around 50 boxes of rifles and ammunition, as well as a large shipment of medicines.
The men were treated with deference by local FSA leaders and were carrying large bundles of cash. They also received two prisoners held by rebels, who were allegedly members of the pro-regime militia, the Shabiha.
The influx of weapons has reinvigorated the insurrection in northern Syria, which less than six weeks ago was on the verge of being crushed.
The move to pay the guerrilla forces' salaries is seen as a chance to capitalise on the sense of renewed confidence, as well as provide a strong incentive for soldiers and officers to defect. The value of the Syrian pound has fallen sharply in value since the anti-regime revolt started 16 months ago, leading to a dramatic fall in purchasing power.
The plan centres on paying the FSA in either US dollars or euros, meaning their salaries would be restored to their pre-revolution levels, or possibly increased.
Defecting to the FSA is difficult because the shabbiha militia is attached to every army unit and is there to prevent that from happening. A few defectors have been caught and made an example of by the shabbiha -- a quite unpleasant death. Whether it will deter mass defections is unknown, but the prospect of a boost in pay might do the trick.