Diasporic mobilization studies often incorporate collective emotions into the discussion of movement strategies, less we knew about how emotion becomes the language by which they communicate collective responsibility after the protests. The purpose of this paper is to draw from participant observation research to explore how diasporas construct the language of collective emotions to sustain their commitment to the transnational mobilization project during and after the homeland protests. Drawing on ten months of participant observations in the USA, the author observed how members of a Hong Kong diaspora group, the Black Bauhinia Society (BBS), transformed their project from a transnational protective gear sourcing action during the Hong Kong Anti-Extradition Bill Movement into a global medical personal protective equipment (PPE) sourcing action during the COVID-19 pandemic. During homeland uprising, BBS recruits participants using a set of compassion language that encompasses the suffering stories of homeland dissidents and the members’ expression of guiltiness for staying afar. The compassion talk reinforces the transnational ties between BBS members and Hong Kong dissidents over the process of resource mobilization. When the homeland movement ceased during the pandemic, BBS transformed their compassion talk to politicize charitable actions and recruit volunteers and donors to source PPE for Hong Kong. This paper contributes to the emerging discussion on how the diaspora mobilizes after the protest by showing how the language of collective emotion cultivates commitments and sustain collective identity after the protests.