On WhatsApp for Android you can easily block a contact, so you won’t receive any message from that blocked person. To unblock / block a contact on WhatsApp for Android, do as follows:
1. Open WhatsApp on your Android device2. Tap the 3dot icon on the top right and then touch the Settings.3. Tap the Account option and go to the Privacy settings4. Under the Messaging settings, tap to open the Block Contacts option5. Now, tap the Add icon on the top right and start selecting the contacts to block6. To unblock a contact on WhatsApp for Android, open the list of blocked contacts, tap the one to unblock and touch the Unblock option