When a man performs a Shraddha in honour of the departed manes on earth belonging to another person, the departed manes render both the gift of that earth and the Shraddha itself fruitless.
पारक्ये भूमिदेशे तु पितॄणां निर्वपेत् तु यः॥ तद्भूमिं वापि पितृभिः श्राद्धकर्म विहन्यते।