Is it permissible to draw a hand showing the index and middle fingers beneath the Hadith: "I and the guarantor of the orphan are in Paradise like these two," and he gestured with his two fingers, taking into account the saying of some that this represents the hand of the Messenger?

If the drawing is not intended to represent the Prophet, peace and blessings be upon him, but rather to clarify the meaning and the proximity of the guarantor of the orphan to him, then there is no harm in it. This falls under what scholars call "musalsal" (chained narration), similar to what some of the Salaf did when narrating what they heard from the Prophet, peace and blessings be upon him, to clarify the meaning. An example of this is what Al-Bara' ibn 'Azib did when he gestured with his hand as the Prophet, peace and blessings be upon him, gestured when asked about sacrifices. Another example is what is narrated in the description "I and the guarantor of the orphan will be in Paradise like this," where the narrator pointed with his index and middle fingers.