Swedish Vikings extended mostly toward what is now Russia and Ukraine, using Volga, Don and Dniepr as major communication/transport channels [0]. This brought them into contact with the Khazar Khanagate at the mouth of Volga [1] and the Volga Bulgars [2] (both muslim at the time). When Vladimir (half viking) had to choose a religion for his Kievan Rus, Islam was one of the choices [3] (rejected because it would forbid the joy of drinking, see link).
So there was ample cultural contact with Islam, a religion actively proselytizing. It lasted about 150-200 years. That some influence made it back to Sweden should not be surprising.
[0] https://en.wikipedia.org/wiki/Volga_trade_route [1] https://en.wikipedia.org/wiki/Khazars [2] https://en.wikipedia.org/wiki/Volga_Bulgaria [3] https://en.wikipedia.org/wiki/Vladimir_the_Great