Sayyiduna Hudhayfah (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him) that he (peace and blessings be upon him) said: "Whoever spits in the direction of the qiblah, on the Day of Resurrection his spittle will be between his eyes; and whoever eats of this foul vegetable, let him not come near our mosque." He (peace and blessings be upon him) said it three times.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5055