"Thank you for what you and your friends are doing to help children in Yemen," the Hollywood star wrote in a signed note to Ayaan Moosa and Mikaeel Ishaaq, both six. "I'm sorry I'm not able to buy a lemonade from you, but I'd still like to make a donation to your stand."
Helped by their parents, the pair set up their sweet-hearted and sour-tasting venture on the street where they live in east London around a month ago. Together they serve freshly-squeezed lemonade for £2 ($3) to passers-by.
"They have nothing, like, the things you need to survive. They have no water, food, oil. And we have all of those things and that's why we help them," Moosa told NBC News about Yemen, the Arab world’s poorest nation, which has been convulsed by civil war since 2014.
Read the full story on NBCNews.com