It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever does not accept an invitation disobeys Allah and His Messenger."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 5263
Hadith Gradingحکم دارالسلام:حديث صحيح لغيره ، وهذا إسناد ضعيف لضعف العمري .