Princeton undergrads should apply for funding via the Student Activities Funding Engine (SAFE) http://www.princeton.edu/studentfunding. Among other awards, the Dean's Fund for Study Abroad offers competitive awards to students on financial aid for summer language study. Application is via SAFE. The application deadline is generally in early March, but check https://oip.princeton.edu/our-programs/study-abroad/financial-matters/summer for details.
Princeton graduate students should apply to PIIRS for summer-language funding, also via SAFE (see http://piirs.princeton.edu/funding/graduate-support); the deadline for PIIRS graduate-funding applications is generally in early to mid-February.
For those of you interested in study abroad, you will first want to consult the website of Princeton’s Office of International Programs (www.princeton.edu/oip), and its Study Abroad Program page (www.princeton.edu/oip/sap). You will find important information there about both funding opportunities and University credit. Please note, if you want to earn Princeton credit for courses taken in any summer program, you must consult the Office of International Programs well before you head off to study in your program.
Students seeking funding from the Department or Program in Near Eastern Studies should consult the following: Graduate students can obtain information from the Department website (https://nes.princeton.edu/) or Program website (http://www.princeton.edu/nep/). Please note that as of AY 2018-2019, the FLAS (Title VI) funding is not currently available through the Program in Near Eastern Studies (this remains true as of fall 2021). Undergraduates should apply directly for Department and Program funding via the SAFE portal at http://www.princeton.edu/studentfunding/.
One fully-funded Arabic program is the U.S. State Department's Critical Language Study (CLS) fellowship, administered by the American Councils for International Education. Information on this fellowship can be found at www.clscholarship.org. Note that the application deadline for CLS scholarships is generally in November, so plan ahead! Greg Bell was the academic director for the CLS program in Oman in 2010 and 2011 and can speak to you about the CLS experience, as can Princeton students who have been awarded CLS grants in the past (see Princeton Resource People on the Our Princeton Summer Students page). Dr. Steve Gump, Associate Director of Fellowship Advising in the Office of International Programs also runs information sessions and essay-writing workshops for prospective CLS students. More information about these can be found at www.princeton.edu/oip/fellowships.
Finally, be sure to look into any scholarships or funding offered by language programs themselves. Many programs have money to help those who wish to attend them, with awards based on need and/or qualifications. This is particularly true of U.S.-based programs such as Middlebury, which tend to be costly, but which often have funding available.